which becomes:

This has the advantage that it’s not a breaking change; currently`:=` fails to compile. Adding support for this new operator includes mimicking with`const` what CoffeeScript currently does with`var`, in that it tracks all assigned variables and initializes them together in one`var` statement at the top of the scope.

There is no need to support`?:=`, since by definition constants can’t be reassigned.

This has the advantage that it’s not a breaking change; currently`:=` fails to compile.`const` variables must be assigned and declared in the same operation, so such declarations would happen in JavaScript at the same place in your code (unlike`var` declarations which happen at the top of the scope). There is no need to support`?:=`, since by definition constants can’t be reassigned.

Nothing else would be changed by adding this new operator. Normal assignment is handled as it is today, with`var`. Even though using`:=` would cause`const` to be in the generated output, this feature is “opt in” like modules and the same warning would apply about transpiling CoffeeScript’s output.